Conventionally, there has been proposed an apparatus for sucking up and spraying a liquid by utilizing a phenomenon in which a lower portion of an impeller or a rotor is immersed in the liquid and the impeller or the rotor is rotated, whereby the liquid rises up on a surface of a peripheral wall of the impeller or the rotor.
For example, in Japanese Utility Model Application Laid-Open Publication No. S50-156810 (Patent Literature 1), disclosed is a centrifugal-force-type liquid spraying apparatus in which a liquid is sucked up from a liquid suction pipe through the rotation of an impeller and is sprayed against an impact body, thereby pulverizing sprayed liquid particles. This liquid spraying apparatus is equipped with: the impeller which includes a liquid passage formed by overlapping two rotating plates and a fan provided on at least one of these rotating plates; and the liquid suction pipe provided in the central portion of said impeller so as to communicate with the liquid passage. Upon supplying power to a motor and driving the impeller and the liquid suction pipe, water inside a water tank rises along an inner wall of the liquid suction pipe and flows from a water passing hole into the liquid passage of the impeller. The water flowing into said liquid passage is accelerated by centrifugal force and scattered outwardly.
In addition, in Japanese Patent Application Laid-Open Publication No. 2008-261609 (Patent Literature 2), disclosed is a mist generation apparatus which includes a rotor capable of scattering a liquid around by centrifugal force. As one embodiment of this mist generation apparatus, the mist generation apparatus in which a hole part is formed inside an axial part of the rotor is disclosed. In this embodiment, it is disclosed that when the rotor is rotated, water located inside the hole part of the axial part rises in a manner of film along an inner peripheral surface of the hole part by the action of centrifugal force, reaches an upper surface of a rotating plate, is subsequently accelerated on the upper surface of the rotating plate by the centrifugal force and thereby becomes water-film, and is scattered toward around the rotating plate.